Increased LH and FSH release from the anterior pituitary of ovariectomized rat, in vivo, by copper-, nickel-, and zinc-LHRH complexes.
Abstract The effect of Cu 2+ , Ni 2+ , Zn 2+ and their complexes with LHRH on the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) was estimated in in vivo experiments with the use of the method proposed by Ramirez and McCann. Ovariectomized, estradiol, and progesterone pretreated rats were injected intraveneously either with LHRH alone, a metal ion alone, a mixture of metal and hormone, or a metal-LHRH complex. A metal alone or a mixture of it with LHRH did not affect gonadotropin release at all or no more than LHRH alone. However, the complex of Cu 2+ with LHRH brought about a high release of LH and even higher release of FSH. This indicates that copper complex i…
Binding of Cu2+, Zn2+, and Ni(2+)-GnRH complexes with the rat pituitary receptor.
Complex of copper with the gonadotropin-releasing hormone, GnRH, competed more efficiently for the GnRH receptor than native GVRH, while complexes of nickel with GnRH and zinc with GnRH had slightly lower affinity. Copper ion added to the incubation mixture inhibited the buserelin binding to the receptor.